git push tags

#from git 1.8.3 you can use
git push --follow-tags
#single tag push
git push origin <tag_name>
#All tags (if possible use --follow-tags 'cause it's safer)
git push --tags

git tag -a v1.2 
git push origin v1.2

git tag -a version.number -m "Tag Message"
git push origin <tagname>